Submental Perforator Flap for Soft-Tissue Reconstruction in Bisphosphonate-Related Osteonecrosis of the Jaws

Repair of postoperative defects of oral cancer with submental island flaps based on vascular pedicles of different states: a multicenter retrospective study

Submental island flap has certain advantages in repairing postoperative defects of oral cancer, and it can often achieve similar or even better effects compared with those of the free tissue flap. In this study, according to the different characteristics of patients and postoperative defects of oral cancer, submental island flaps with different states of vascular pedicle were prepared, and its repair methods, safety, and clinical effects in treating postoperative defects of oral cancer were investigated. 83 patients with oral cancer who met the inclusion criteria were selected. According to the different characteristics of the patients and postoperative defects of oral cancer, the traditional submental island flap vascular pedicle was modified into three different states: submental artery perforator flap, vascular pedicled flap with the anterior belly of digastric muscle but without the submandibular gland (SIF with anterior belly of DM), and vascular pedicled flap with the anterior belly of the digastric muscle and the submandibular gland (SIF with anterior belly of DM and SG). The types of the submental artery and the drainage vein, flap survival, and complications, were observed. The flap was successfully harvested for all patients, and the submental artery could be found or separated for all of them, with the venous drainage to the internal jugular vein in 57 (57/83, 68.67%), to the external jugular vein in 18 (18/83, 21.69%), and to the anterior jugular vein in eight (8/83, 9.64%) cases. Submental artery perforator flap was used for 11 cases, complete necrosis occurred in two cases (2/11, 18.18%), partial necrosis occurred in one case (1/11, 9.09%); SIF with anterior belly of DM was used for 49 cases, complete necrosis occurred in one case (1/49, 2.04%), partial necrosis occurred in four cases (4/49, 8.16%); SIF with anterior belly of DM and SG was used for 23 cases, including chimeric flap combining the submental island flap and the submandibular gland used for 15 cases, there were no cases of complete or partial necrosis. Submental island flap was effective in repairing postoperative defects of oral cancer. Submental island flaps with three different states of vascular pedicle could repair oral cancer-affected tissues with different defect characteristics.

The Role of Bone Grafts in Preventing Medication-Related Osteonecrosis of the Jaw: Histomorphometric, Immunohistochemical, and Clinical Evaluation in Animal Model

Objective

To evaluate the effects of inorganic bovine bone graft (Lumina Bone, Criteria, Brazil) and beta-tricalcium phosphate (β-TCP) graft (ChronOS, Synthes, Brazil) in rats with the risk of developing post-extraction medication-related osteonecrosis of the jaw (MRONJ).

Methods

Eighteen male Wistar rats weighing 350 to 450 g were induced to develop MRONJ using zoledronic acid for 5 weeks. In the sixth week, the right maxillary first molar was extracted. The animals in Group I (G1) did not receive bone grafts after tooth extraction, while Group II (G2) animals received inorganic bovine bone grafts, and Group III (G3) animals received beta-tricalcium phosphate (β-TCP) grafts. Clinical evaluation and histomorphometric and immunohistochemical analyses were performed. ANOVA and Tukey's statistical tests were used and a level of significance was considered to be 5%.

Results

In the clinical evaluation, animals from G2 and G3 did not present clinical manifestations of osteonecrosis, unlike the control group (G1) animals, which presented necrotic bone tissue exposure in all samples. In the histomorphometric evaluation, animals in G3 showed greater formation of bone tissue (66%) and less formation of bone lacuna (18%) than animals in G1 (58%/32%) and in G2 (59%/27%) (P < 0.05). Moderate (++) immunostaining was observed in G2 and G3 for RANKL, TRAP, and OC, while G1 showed moderate (++) labeling for OC and mild (+) immunostaining for TRAP and RANKL.

Conclusions

Greater formation of bone tissue and fewer bone lacunae were found in animals treated with β-TCP. In clinical evaluation, bone graft groups presented with the clinical manifestation of MRONJ and showed higher intensity of immunostaining for TRAP and RANKL. Despite the limitations of experimental animal studies, the results of this work may assist in the development of future clinical research for the prevention of MRONJ.

The efficacy of mylohyoid muscle flap use in surgical treatment of 'krokodil' drug-related osteonecrosis of the mandible

The aim of this study is to show the effectiveness of the use of mylohyoid muscle flap in surgical treatment of stage 1 and 2 Krokodil drug-related ON of mandible. Retrospective study of patients with stage 2 Krokodil drug-related ON of distal mandible was performed. Regarding to the used surgical technique the patients were divided into two groups (groups 1 and 2). In group 1(control group) the wound was closed only by the local mucoperiosteal flaps, while in group 2 (experimental group) the wound was closed by combining mylohyoid muscle flap and local mucoperiosteal flaps. 24 patients were included in this study (15 patients in the group 1 and 9 patients in the group 2). In all patients of experimental group the postoperative period was uneventful and no recurrence occurred. In group 1 recurrence was found in 7 patients, which is significantly higher than in group 2 (χ²=5.9, p=0.015). Disease recurrence occurred as wound dehiscence during 4-10 postoperative days. Within the limitations of the study it seems that the adoption of the mylohyoid muscle flap as double-layer closure technique is an effective and predictable method for the treatment of such patients and, therefore, should be chosen whenever deemed appropriate.

[Diagnostic value of chromato-mass-spectrometry in patients with drug-induced jaws osteonecrosis]

In patients with drag-induced jaw osteonecrosis which developed in cancer patients due to administration of bisphosphonates for metastases, the microflora of the oral cavity was examined by chromatography-mass spectrometry (HMS). The method of HMS can be used as an additional method of diagnostics in complex clinical cases with ineffective treatment.